Way back in the day I put a Mr Gasket V Gate shifter in my Duster. It requires a lot of cutting of the tunnel. A better choice is the Hurst Ram Rod shifter much more compact and it shifted better. I still have both of those shifters. I may end up installing one in one of my projects.
The Long shifter is the best out there. I used their T handle shifter on my Jericos until they came out with the Pistol grip.